title: Characterization of competence and biofilm development of a Streptococcus sanguinis endocarditis isolate.
abstract: Streptococcus sanguinis is an oral commensal bacterium and endogenous pathogen in the blood, which is generally naturally competent to take up extracellular DNA. Regarded as a stress response, competence development enables S. sanguinis to acquire new genetic material. The sequenced reference strain SK36 encodes and expresses the genes required for competence (com) and uptake of DNA. Isolated from blood cultures of a confirmed case of infective endocarditis, strain 133-79 encodes all necessary com genes but is not transformable under conditions permissive for competence development in SK36. Using synthetic competence-stimulating peptides (sCSP) based on sequences of SK36 and 133-79 comC, both strains developed competence at similar frequencies in cross-transformation experiments. Furthermore, downstream response pathways are similar in strains SK36 and 133-79 because platelet aggregation and biofilm formation appeared unaffected by CSP. Collectively, the data indicate that strains SK36 and 133-79 respond to CSP similarly, strongly suggesting that endogenous production or release of CSP from 133-79 is impaired.
authors.affiliation: College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
authors.forename: L
authors.initials: L
authors.lastname: Zhu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: J
authors.initials: J
authors.lastname: Fan
authors.forename: M C
authors.initials: MC
authors.lastname: Herzberg
authors.forename: J
authors.initials: J
authors.lastname: Kreth
mesh_terms: D058491:Bacterial Load; D001426:Bacterial Proteins / Q000235:genetics* / Q000494:pharmacology; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development; D004697:Endocarditis, Bacterial / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D010641:Phenotype; D011401:Promoter Regions, Genetic / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000382:microbiology*; D013298:Streptococcus sanguis / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics; D014169:Transformation, Bacterial / Q000187:drug effects / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; C120829:ComX protein, Streptococcus; D014157:Transcription Factors; C423628:competence factor, Streptococcus